In the medical arts there are known a wide variety of devices for applying thermal environment externally to portions of a human body for the medical treatment thereof. For purposes of this application, the term "thermal" is intended to denote both hot and cold thermal application, thus, whirlpool baths, ice packs, hot water bottles, heating pads, and the like all are examples of such technology. Another is a hydrogel material which is sold under the trademark Elastogel.
In general, the placement of discrete thermal environment elements such as cold packs and hot water bottles or similar elements, and retention thereof with respect to a human extremity has posed significant difficulties. Accordingly, in the prior art it has been necessary to envelope the entire limb within a hot or cold thermal appliance even though the thermal environment was actually required only at a specific position or location to treat a corresponding specific portion of the limb. The application of thermal environment to an entire limb when only a localized portion required it is of course inefficient from the energy usage standpoint, but in addition it made for ineffective thermal environment therapy because for the typical patient the application of thermal environment to an entire limb, especially at temperatures varying widely from ambient temperature, quickly becomes very uncomfortable or even painful. The patient thus will not tolerate such application of thermal environment for long periods of time, and as a result the duration of thermal application therapy was necessarily limited.
There are also known garments in the nature of support stockings, wraps, and the like which are adapted to encompass a human extremity such as a leg or a portion thereof. Such support garments typically have been made from resilient elastic fabric or similar material to provide the requisite support function. The above and other expedients have been employed for various purposes including the treatment of circulatory deficiencies, contusions or bruises, muscle system and skeletal problems such as soreness or stiffness, as well as a variety of other conditions.
The art has further contemplated various sorts of apparatus for circulating thermal fluid through sleeves or other limb coverings which are adapted to enclose all or a portion of a human limb. Some such apparatus include pads or covers that are placed over a human limb and some include fluid chambers through which a heat transfer medium is pumped by a suitable pump apparatus to establish and maintain a desired temperature. Among the patents known to me which pertain generally to such apparatus are U.S. Pat. Nos. 4,338,994, 4,149,529, 3,967,627, 3,918,458, 2,415,455, 2,272,481, 3,186,404 and Italian patent 442,309.
Another prior art patent of interest regarding the present invention is U.S. Pat. No. 4,370,975, which discloses a sheath for receiving a human extremity such as an arm or leg, the sheath being divided into longitudinally spaced inflatable air cells encircling the limb, and a source of air pressure which is operable to inflate the respective cells to predetermined pressure magnitudes repeatedly in a timed sequence to produce a gradient pressure. The apparatus in this latter patent has been used for the treatment of lymph system disorders such as Parkes-Weber Syndrome which is characterized by the accumulation of lymphatic fluid in a human limb and resultant swelling of the limb to a much greater than normal size.
Notwithstanding the above and other expedients known in the prior art, practitioners of the art have continued to seek improved means of providing external application of thermal and/or pressure treatment to portions of the human body to treat a variety of disorders. Much recent activity in this regard has been undertaken in the sports medicine field, but medical practice in general is replete with examples of such treatments.